How Are Bicycles Like Airplanes and Stilt Walkers Too

[Ranb]

Basic bicycle math is much more complicated than basic airplane math.

Any chance we are going to see an example of both?

Ranb

 

[Ranb]

.....People tried to "rudder them", rudder their airplanes. Such planes won't fly. An airplane of course can have a "rudder", but planes turn by banking.

The point about the Wright Brothers and their being bicycle riders cannot be overstated in any sense. They understood how a plane should turn and therefore built a plane that would turn, a plane that worked because they were master bicycle builders, and were enthusiastic riders. They understood their bicycles quite well.........Airplanes turn as bicycles do, they bank. The Wrights were the first builders to understand this.......

It is entirely possible to control the direction of an aircraft without ailerons and using only the rudder. I have done this with models (with one channel control) and during flight training in a Cessna.

From what I have read, the Wright brothers studied bird flight and saw that they turned by altering the shape of their wings to bank/turn. While being bicycle mechanics helped them build and design their kites, gliders and aircraft, the main reason they succeeded was that they knew the main problem was control, not power. Others who failed before them thought that power was the problem and they could learn to control the plane later. The Wright brothers actually learned to fly before they ever attempted to fly under power.

Ranb

 

[roger]

The measure is calories per passenger mile. You don't have to hang wring about calories you burn while sleeping, nor the energy burned in the factory where the headlights are made.

By that measure, bikes run in the mid 30s (Kcal/mile), cars are 1500 or so, and trains 100 or so.

This is trivially googe-able.

 

[Bikewer]

I have a book called Bike Cult by David Perry. It's a sort ok encyclopedia of cycling in all it's aspects. Perry devotes a chapter to this very topic, citing scientific papers and studies that purport to explain how bicycles do what they do.
I admit most of it was beyond me.
Good luck finding a copy; it's evidently out of print and Amazon is showing them staring at 80 bucks.

 

[Belz...]

That's RIGHT!!!!!

Why is that?!!!!!!

Bike's balance themselves!!!!!!!

That's odd. In my experience bikes usually fall down when unattended.

 

[Neutiquam Erro]

That's odd. In my experience bikes usually fall down when unattended.

Maybe somebody's left his training wheels on?

 

[quarky]

Six pound bikes have been built and ridden. Quite extraordinary.
I learned to ride a unicycle in less time than it took to ride a bike. Its really pretty easy.

 

[Neutiquam Erro]

Six pound bikes have been built and ridden. Quite extraordinary.
I learned to ride a unicycle in less time than it took to ride a bike. Its really pretty easy.

Is it truly a skill that anyone can acquire? Many people find juggling easy - it has always been impossible for me. Many people are unable to sing on-pitch - this has always been easy for me.

 

[zooterkin]

Is it truly a skill that anyone can acquire?

I've tried it a few times, and haven't got the hang of it yet, though I think it's one of those things that just clicks at some point; I may give it another go this year. I can ride conventional bikes, and recumbents, so it's not lack of balance that's my problem.

 

[Patrick1000]

The Reference Article Above is A Fairly Good One

Any chance we are going to see an example of both?

Ranb

The Reference Article Above is A Fairly Good One....

A good example of "Bicycle Math"

Airplane stuff is simple enough, you can find it anywhere, smart middle schoolers can do airplanes.....

 

[Patrick1000]

That's amazing about the unicycle. I think I would be afraid to even try one.

Six pound bikes have been built and ridden. Quite extraordinary.
I learned to ride a unicycle in less time than it took to ride a bike. Its really pretty easy.

That's amazing about the unicycle. I think I would be afraid to even try one. Looks so very very difficult to me.

 

[Patrick1000]

If you get them started downhill and don't lock the steering,.....

That's odd. In my experience bikes usually fall down when unattended.

If you get them started downhill and don't lock the steering, many bikes will go fairly well for a while, without a rider. It is easy enough to ride with "no hands", ride hands free correct? I can even turn my bikes without touching the handlebars, my best bike no problem to do this, easy....

A bike is like a "stilt walker", ALWAYS MOVING, however slowly to that new place of dynamic balance. Think of a world class gymnast on the pommel horse, or doing leg circles as part of a floor exercise. If they stop, they drop. Bike the same way. A bike can hardly be moving at all, but HARDLY does count for something, just a tiny bit of movement and your bike can find, in a very real sense all on its own, that perfect place of dynamic balance.

That said, there is a difference with respect to bicycles balancing with or without a rider. The machine is relatively unique given the size of the rider with respect to the size of his/her ride. As mentioned, I weigh 10 times more than my favorite bicycle.

 

[Patrick1000]

No one has come up with THE answer Bikewer....

I have a book called Bike Cult by David Perry. It's a sort ok encyclopedia of cycling in all it's aspects. Perry devotes a chapter to this very topic, citing scientific papers and studies that purport to explain how bicycles do what they do.
I admit most of it was beyond me.
Good luck finding a copy; it's evidently out of print and Amazon is showing them staring at 80 bucks.

No one has come up with THE answer Bikewer in terms of a clear and comprehensive mathematical model. The stilt walking analogy qualitatively is very much on target.

 

[JoeTheJuggler]

As someone who does lots of stiltwalking, I was interested to hear the comparison, but I don't think anyone has explicated it here.

I can provide this much anyway: stiltwalkers balance pretty much the same way people walking on two feet on the ground balance. If my center of mass shifts to a point not above my feet, I have to pick up my feet and move them underneath.

People first learning to stiltwalk, tend to try to dig in their feet and maintain balance with their upper body. That rarely works. Consider a person standing (stiltless) on two feet with the feet side by side, as is normal (as opposed to a karate-style "T" stance or some such). If you shove that person in the chest, that person can't stay balanced by digging in the feet. That person will stay up by stepping backward, at least with one foot.

OK. . . so how is balancing on a bicycle like this? Is it just the point that it's not the gyroscopic force of the wheels? Or is it maybe the point that a dynamic balance is easier for most of us to maintain than a static balance?

ETA: On a point tangential to the gyroscope issue: I used to train people on Segways and lead Segway tours, and I was dismayed by how many people (even my boss) were telling people bogus notions of how Segways work. They frequently said the gyroscopes hold you up, or they balance you the same way a gyroscope in the Space Shuttle works. In fact, for that to be true, the gyroscope would have to be about as massive (or maybe more--I've never calculated it) as the entire Segway, when in fact, the 5 gyroscopes in a Segway occupy a small box about 2" x 3" by 1" deep or thereabouts. The gyroscopes are only sensory. They proved information on the platform tilt and indirectly about the center of mass of the rider. The cpu then "tries" (to use the pathetic fallacy) to keep the wheels centered under that center of gravity. This elegant notion explains how they balance and how they go and stop by leaning your mass.

 

[Patrick1000]

I am aware of the Wright history in great detail.....

It is entirely possible to control the direction of an aircraft without ailerons and using only the rudder. I have done this with models (with one channel control) and during flight training in a Cessna.

From what I have read, the Wright brothers studied bird flight and saw that they turned by altering the shape of their wings to bank/turn. While being bicycle mechanics helped them build and design their kites, gliders and aircraft, the main reason they succeeded was that they knew the main problem was control, not power. Others who failed before them thought that power was the problem and they could learn to control the plane later. The Wright brothers actually learned to fly before they ever attempted to fly under power.

Ranb

I am aware of the Wright history in great detail.....The insight with respect to how a plane would turn, by way of BANKING, CAME FROM THEIR EXPERIENCE AS BICYCLE RIDERS, about that, there can be no doubt.

The Wrights studied many things. THE WRIGHT BROTHERS WERE MOST DECIDEDLY NOT SIMPLE BLUE COLLAR TINKERERS, THEY WERE TRULY MEN OF IMMENSE GENIUS. They had a "wind tunnel" which was a bicycle with a rim mounted on it to which they could attach things and in so doing assess the aerodynamic behavior of this and that. They themselves referred to it as their "BICYCLE APPARATUS". Their plane prop was driven by a chain with a toothed wheel, just like their bicycles and so on.

It is not a coincidence that of the 5 Wright Brothers bicycles known to be in existence, one is in the Smithsonian Aerospace Museum and one of the others is at the U.S. Air Force Museum just outside of Dayton Ohio. My first trips to both places were to see the Wright bicycles, as relatively interesting as the other stuff is. MX missiles are a dime a dozen, but A WRIGHT BICYCLE, NOW THAT!!!!!! IS SOMETHING SPECIAL........

 

[Patrick1000]

To say a bike works like a "stilt walker" is not to say a rigorous

As someone who does lots of stiltwalking, I was interested to hear the comparison, but I don't think anyone has explicated it here.

I can provide this much anyway: stiltwalkers balance pretty much the same way people walking on two feet on the ground balance. If my center of mass shifts to a point not above my feet, I have to pick up my feet and move them underneath.

People first learning to stiltwalk, tend to try to dig in their feet and maintain balance with their upper body. That rarely works. Consider a person standing (stiltless) on two feet with the feet side by side, as is normal (as opposed to a karate-style "T" stance or some such). If you shove that person in the chest, that person can't stay balanced by digging in the feet. That person will stay up by stepping backward, at least with one foot.

OK. . . so how is balancing on a bicycle like this? Is it just the point that it's not the gyroscopic force of the wheels? Or is it maybe the point that a dynamic balance is easier for most of us to maintain than a static balance?

To say a bike works like a "stilt walker" is not to say a rigorous mathematical model of both would prove the activities were identical, it is to draw attention to a bicycle's always moving to find a new place of balance, and the operative word is NEW.

I would imagine you could stand still on your stilts JoeTheJuggler, so right there, you are different from a bicycle. A bicycle cannot stand still at all to balance, impossible.

Now, if you were on stilts that just touch the earth as "points", say a couple/four square inches in area, now I bet you couldn't balance standing still. Or if you could, I would take away more surface area from your "feet", say make your earth contact points one square inch each, keep reducing that area until you MUST MOVE TO MAINTAIN YOUR BALANCE. NOW YOU ARE A BICYLCE JOETHEJUGGLER.

 

[Belz...]

If you get them started downhill and don't lock the steering, many bikes will go fairly well for a while, without a rider. It is easy enough to ride with "no hands", ride hands free correct? I can even turn my bikes without touching the handlebars, my best bike no problem to do this, easy....

What are you on about ? Bicycles are kept upright because of constant, small adjustements to the weight distribution. What's mysterious about that ?

 

[Patrick1000]

The thing with Bikes and gyroscopes is interesting JoeTheJuggler

As someone who does lots of stiltwalking, I was interested to hear the comparison, but I don't think anyone has explicated it here.

I can provide this much anyway: stiltwalkers balance pretty much the same way people walking on two feet on the ground balance. If my center of mass shifts to a point not above my feet, I have to pick up my feet and move them underneath.

People first learning to stiltwalk, tend to try to dig in their feet and maintain balance with their upper body. That rarely works. Consider a person standing (stiltless) on two feet with the feet side by side, as is normal (as opposed to a karate-style "T" stance or some such). If you shove that person in the chest, that person can't stay balanced by digging in the feet. That person will stay up by stepping backward, at least with one foot.

OK. . . so how is balancing on a bicycle like this? Is it just the point that it's not the gyroscopic force of the wheels? Or is it maybe the point that a dynamic balance is easier for most of us to maintain than a static balance?

ETA: On a point tangential to the gyroscope issue: I used to train people on Segways and lead Segway tours, and I was dismayed by how many people (even my boss) were telling people bogus notions of how Segways work. They frequently said the gyroscopes hold you up, or they balance you the same way a gyroscope in the Space Shuttle works. In fact, for that to be true, the gyroscope would have to be about as massive (or maybe more--I've never calculated it) as the entire Segway, when in fact, the 5 gyroscopes in a Segway occupy a small box about 2" x 3" by 1" deep or thereabouts. The gyroscopes are only sensory. They proved information on the platform tilt and indirectly about the center of mass of the rider. The cpu then "tries" (to use the pathetic fallacy) to keep the wheels centered under that center of gravity. This elegant notion explains how they balance and how they go and stop by leaning your mass.

The thing with Bikes and gyroscopes is interesting JoeTheJuggler because often times you'll hear high level scientists refer to gyroscopic mechanisms as explanatory in the case of bicycle balancing. It's a case of smart people jumping to an obviously wrong conclusion type of situation.

A bicycle that is barely/scarcely/hardly moving at all, is moving nonetheless. But barely/scarcely/hardly moving is nothing more than barely/scarcely/hardly moving, and as such, there is no meaningful gyro effect with respect to the bicycle's balancing.

Gyro effects do play a role with regard to some aspects of turning on a bike, a subject for perhaps another day.

I think I walked on stilts a few times as a boy. It was fun!!!

 

[Patrick1000]

No, one need not be riding for a bicycle to balance. A bicycle will balance on its..

What are you on about ? Bicycles are kept upright because of constant, small adjustements to the weight distribution. What's mysterious about that ?

One need not be riding for a bicycle to balance. A bicycle will balance on its own, without a rider. If you mean to say that the "bicycle adjusts its own weight" then of course you would be correct.

What is mysterious about it is that no one knows exactly how a bicycle does this. Take a look at the article I referenced above. Not very straight forward is it?

 

[zooterkin]

It is easy enough to ride with "no hands", ride hands free correct? I can even turn my bikes without touching the handlebars, my best bike no problem to do this, easy....

What does that have to do with anything? You're still making adjustments to the balance with your body to keep the bike upright even if you're not touching the handlebars.